This invention is an improvement to U.S. Pat. No. 5,104,150 issued Apr. 14, 1992 to Shannon Bard and Thomas N. Prassas, the inventors of the present invention. The teachings of U.S. Pat. No. 5,104,150 are incorporated herein by reference. Our prior patent discloses an irrigation fitting that can connect together either irrigation tubing or threaded garden hose with the same fitting. This invention extends that concept to provide a fitting that can fasten directly to a pipe thread riser of the type generally used to feed sprinkler heads from networks of underground pipes so that, for the first time, garden hose, porous hose, and impervious tubing can all be connected to a standard pipe thread sprinkler system with just one universal fitting.
To insure efficient water usage, modern irrigation systems deliver water in controlled amounts precisely to the desired plants so as to avoid runoff and evaporation. Two slightly different prior art designs have matured that are very popular. One employs impervious plastic tubing, usually polyethylene, to convey water through a collection of tee fittings, elbows, and couplings so as to distribute the water to the various plants. At each chosen location, a point source emitter attaches to the tubing with a barbed connector inserted through the tube wall.
Another prior art design employs pervious or porous tubing, also known as soaker hose in the art, that sweats water along its entire length so as to create a line source suitable for rows of plants and the like. Porous pipe may also be connected together with elbows, couplings, and tee shaped fittings to create an elaborate distribution network.
Since the above two prior art systems have evolved separately, they generally do not use compatible fittings and are not connectable to each other. It would be advantageous, however, if they could be combined to obtain in a single water circuit the benefits of both types of distribution systems. For example, impervious tube allows the exact positioning of just the right kind of point source emitter to provide a spray pattern optimized for the task, or perhaps a drip at the base of a plant. Porous hose, on the other hand, is simpler to assemble and maintain. It can be buried underground safe from frost, erosion, and evaporation. But building up a complex water distribution system in either system requires a lot of different parts to be combined and joining both systems into one was not practical until the fitting disclosed in our above referenced patent became available.
Still older prior art systems use underground pipe with standard pipe threads to feed a series of sprinkler heads or bubblers through threaded risers that protrude from the surface of the ground. This invention allows garden hose, porous hose, and impervious tube to all be connected to such an underground system riser.